This invention relates generally to a ring mechanism for retaining loose-leaf pages and, more particularly, to an improved mechanism for opening and closing ring members and for locking closed ring members together.
A ring mechanism typically retains loose-leaf pages, such as hole-punched papers, in a file or notebook. A pair of hinge plates are supported within a housing in joined relation for loose pivoting motion relative to the housing. The housing is generally narrower than the joined hinge plates when they are in a coplanar position (180°). So as the hinge plates pivot through the coplanar position, they deform the housing and cause a spring force that urges them to pivot either upward or downward. Ring members mounted on the hinge plates move with the pivoting movement of the hinge plates. The ring members open when the hinge plates pivot upward and close when the hinge plates pivot downward.
Some ring mechanisms include structure (e.g., control slides) located between the housings and the hinge plates to lock the ring members together when they close. The control slides engage upper surfaces of the hinge plates and block the hinge plates from pivoting upward when it is desired to hold the closed ring members together. The control slides move out of engagement with the hinge plates and allow the hinge plates to pivot freely when it is desired to open the ring members. These control slides, however, may have complex shapes or unique parts in order to allow them to interact with the hinge plates to block or allow the pivoting movement of the hinge plates. Therefore, they may be harder to fabricate or may require multiple components for proper operation (e.g., a travel bar and separate blocking elements). Thus, ring mechanisms incorporating these known control slides can be time consuming and costly to produce.
Accordingly, it would be desirable to provide a ring mechanism that is easy to make and that includes a simplified travel bar.